In the field of numerically controlled (NC) machining a machine tool repeatedly passes over a stock. Commonly, a milling tool is used to mill the surface of the stock, thereby removing a small volume of the stock. A typical NC machining process involves of the order of 250,000 individual tool movements, and sometimes many more.
When a new machining process is developed a number of problems may occur, including, for example, unwanted collisions between the machine tool and the stock, and unexpected machining errors resulting in too much or too little material being removed from the stock. Traditionally a new machining process is verified by performing a test milling on a soft, inexpensive material. However, this testing process is expensive and time consuming, and analysis is limited to observational techniques.
More recently, simulation methods have been developed for simulating the movements of the tool with respect to the stock. Each movement of the tool is referred to as a sweep, and the volume represented by one sweep of the tool is known as the swept volume. In a typical simulation method the original volume of the stock is determined and then iteratively reduced by subtracting the swept volume of each tool movement from the original raw stock. However, known methods suffer significant problems in terms of processing speed and memory requirements.